This unit, which is jointly administered under W. E. Bunney, Jr., Chief, Biological Psychiatry Branch, and Richard J. Wyatt, Chief, Adult Psychiatry Branch, has long conducted studies on basic and clinical aspects of sleep in man and animals. It has made contributions to the basic neuropharmacological control of sleep and nocturnal neuroendocrinology, clinical use and abuse of sleeping pills, affective illness, schizophrenia, insomnia, childhood enuresis and obsessive-compulsive disorder, Gille de la Tourette's syndrome, dementia, and adult obsessive-compulsive disorder. Our studies suggest that patients with primary affective illness have a supersensitive cholinergic system both when ill and when in remission. Progress has been made in identifying an endogenous sleep factor in sleep-deprived rat brain. Local glucose utilization is down by approximately 30% throughout the brain during NREM sleep.